Question

TWO GENTLEMEN OF VERONA - A.J.Cronin
. Why did the two boys survive only on black bread and figs, despite making a decent earning? 

Answer 1

The boys used to worked very hard daily but still did not spend their earnings for buying proper food and clothes because they had to save the money for their sick sister who was in a hospital.

Answer 2

Two Gentlemen of Verona:

In this poem, the two boys survived only by eating black bread and figs because all their earning got spent to their sister as their mother died early and father a well-known singer became a victim in the world war.  

She was suffering from Tuberculosis of spine due to winter. She was hospitalized due to her illness and all the money earned is sufficient to buy tablets and other hospital expenses to their sister.